MOSCOW – Leading Russian activists pledged on Monday to boycott a new draconian law that they warn will help the Kremlin stifle critics with a mixture of repression, fines and inspections of non-governmental organizations.

A law comes into force Wednesday obliging NGOs that receive foreign funding and are involved in loosely defined political activities to register as foreign agents. Rights defenders and civil society activists see it as a tool intended to erode their credibility in the public eye and make it easier for the government to crack down on them.

"This law is infamous and immoral," said Lyudmila Alexeyeva, the 85-year-old leader of the Moscow Helsinki Group, a human rights watchdog.

The new law is part of a series of repressive bills passed by the Kremlin-controlled parliament since President Vladimir Putin began his third presidential term in May. Along with a campaign of arrests and searches targeting opposition activists, they are seen as Putin's response to a series of mass street protests against his rule.

Putin defended the new law on NGOs as necessary protection against foreign meddling in Russian political affairs. But Alexeyeva and other Russian NGO leaders said they need to tap foreign funds because local business is afraid of bankrolling Kremlin critics.

They said they don't consider themselves a conduit of foreign influence and pledged to ignore the new law.

"We are working for the benefit of our citizens, not at the behest of a foreign state," Alexeyeva said. "And we aren't going to slander ourselves."

Russia's only independent vote monitoring group, Golos, and a widely respected rights group, Memorial, were also among those who pledged to boycott the new law.